/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.dx.dex.file;

import com.android.dx.rop.annotation.Annotation;
import com.android.dx.rop.annotation.Annotations;
import com.android.dx.util.AnnotatedOutput;
import com.android.dx.util.Hex;

/**
 * Set of annotations, where no annotation type appears more than once.
 */
public final class AnnotationSetItem extends OffsettedItem {

	/** the required alignment for instances of this class */
	private static final int ALIGNMENT = 4;

	/** the size of an entry int the set: one {@code uint} */
	private static final int ENTRY_WRITE_SIZE = 4;

	/** {@code non-null;} the set of annotations */
	private final Annotations annotations;

	/**
	 * {@code non-null;} set of annotations as individual items in an array.
	 * <b>Note:</b> The contents have to get sorted by type id before writing.
	 */
	private final AnnotationItem[] items;

	/**
	 * Constructs an instance.
	 * 
	 * @param annotations
	 *            {@code non-null;} set of annotations
	 */
	public AnnotationSetItem(Annotations annotations) {
		super(ALIGNMENT, writeSize(annotations));

		this.annotations = annotations;
		this.items = new AnnotationItem[annotations.size()];

		int at = 0;
		for (Annotation a : annotations.getAnnotations()) {
			items[at] = new AnnotationItem(a);
			at++;
		}
	}

	/**
	 * Gets the write size for the given set.
	 * 
	 * @param annotations
	 *            {@code non-null;} the set
	 * @return {@code > 0;} the write size
	 */
	private static int writeSize(Annotations annotations) {
		// This includes an int size at the start of the list.

		try {
			return (annotations.size() * ENTRY_WRITE_SIZE) + 4;
		} catch (NullPointerException ex) {
			// Elucidate the exception.
			throw new NullPointerException("list == null");
		}
	}

	/**
	 * Gets the underlying annotations of this instance
	 * 
	 * @return {@code non-null;} the annotations
	 */
	public Annotations getAnnotations() {
		return annotations;
	}

	/** {@inheritDoc} */
	@Override
	public int hashCode() {
		return annotations.hashCode();
	}

	/** {@inheritDoc} */
	@Override
	protected int compareTo0(OffsettedItem other) {
		AnnotationSetItem otherSet = (AnnotationSetItem) other;

		return annotations.compareTo(otherSet.annotations);
	}

	/** {@inheritDoc} */
	@Override
	public ItemType itemType() {
		return ItemType.TYPE_ANNOTATION_SET_ITEM;
	}

	/** {@inheritDoc} */
	@Override
	public String toHuman() {
		return annotations.toString();
	}

	/** {@inheritDoc} */
	public void addContents(DexFile file) {
		MixedItemSection byteData = file.getByteData();
		int size = items.length;

		for (int i = 0; i < size; i++) {
			items[i] = byteData.intern(items[i]);
		}
	}

	/** {@inheritDoc} */
	@Override
	protected void place0(Section addedTo, int offset) {
		// Sort the array to be in type id index order.
		AnnotationItem.sortByTypeIdIndex(items);
	}

	/** {@inheritDoc} */
	@Override
	protected void writeTo0(DexFile file, AnnotatedOutput out) {
		boolean annotates = out.annotates();
		int size = items.length;

		if (annotates) {
			out.annotate(0, offsetString() + " annotation set");
			out.annotate(4, "  size: " + Hex.u4(size));
		}

		out.writeInt(size);

		for (int i = 0; i < size; i++) {
			AnnotationItem item = items[i];
			int offset = item.getAbsoluteOffset();

			if (annotates) {
				out.annotate(4, "  entries[" + Integer.toHexString(i) + "]: "
						+ Hex.u4(offset));
				items[i].annotateTo(out, "    ");
			}

			out.writeInt(offset);
		}
	}
}
